EP0630588A2 - Method and device for transforming flat textile articles - Google Patents

Abstract

Described is a method for reshaping (transforming) textile sheet materials composed of pure natural fibres or a fibre blend by exposing the textile sheet material to sodium hydroxide solution at a concentration of 30 DEG Bé at a temperature of 60 DEG C, treating the textile sheet material for a certain period until a desired shrinkage process has occurred, then removing the sodium hydroxide solution mechanically, especially by squeezing, then mechanically forming the textile sheet material into a new shape, completely removing the rest of the sodium hydroxide solution, and end-treating the textile sheet material in accordance with the subsequent use. <IMAGE>

Description

The invention relates to a method and a device for reshaping textile fabrics.

Such methods have become known in a wide variety of embodiments in the textile industry and in the finishing industry. Such forming processes are used for. B. for the formation of hats and bra cups and cups, and possibly men's underwear and the like. More.

The problem with all laundry articles which are worn directly on the body of the wearer is that the treatment of the textile fabrics with chemicals, plastics and other foreign substances can lead to an allergenization of the wearer. This leads to local contact eczema, skin irritation and general impairments of wearing comfort.

In the manufacture of brassieres in particular, it is known to use synthetic fibers, cotton blended fabrics or pure cotton for the manufacture of brassiere cups or cups.

The former two materials can be subjected to thermal forming in order to produce the necessary brassiere cups or cups. However, this has the disadvantage that the necessity of using synthetic materials and / or impregnation with foreign polymers leads to an impairment of the wearing comfort.

It is known to use pure cotton fibers for such underwear, but this has the disadvantage that it has so far not been possible to produce dimensionally stable, seamless bra cups. In order to remedy this disadvantage, it was previously only known to stiffen accordingly by equipping them with plastic polymers in such a way that they could be subjected to thermal deformation.

When using synthetic resin-containing impregnating agents to achieve dimensional stability, however, there is the disadvantage that these impregnating agents usually contain formaldehyde and that the wearing comfort is therefore greatly impaired.

In addition, the disadvantage of synthetic resin impregnation of such bras is that the elasticity of the fiber and the tensile strength decrease sharply.

From the article "Now-Moldability For All-Cotton Fabrics" by Cooper et al in Textile World, October 1993, pages 91 to 92, it is known to deform cotton fabrics with the use of alkalis.

In this article, the use of 25% sodium hydroxide solution is mentioned, but is rejected as unsuitable, since a very high wash shrinkage occurs in the subsequent washing of the deformed goods of about 10-25%.

In order to reduce the degree of shrinkage which occurs during the subsequent washing, it is proposed to first soak the textile to be deformed, then to squeeze it off in order to remove excess lye. The Textile is then deformed in the mold at 160 ° and dried. The dried alkali is then removed by washing and optionally neutralizing. Then it is dried again.

The frequent moistening and drying of the textile requires a very high amount of energy and time.

Incidentally, the applicant's experience and tests have shown that at the specified shrinkage levels for Cooper of 10-25%, it is impossible for the subsequent neutralization and washing to take place in the mold, but it can be assumed that the latter is known Process the structure treated with sodium hydroxide solution, which carries dried sodium hydroxide solution, must be removed from the mold in order to be neutralized and washed first.

The author therefore rejects the degrees of shrinkage indicated by him in the range between 10-25% and therefore suggests that the preformed goods be impregnated with synthetic resin and deformed under heat. However, this was recognized as disadvantageous in the context of the present invention, because it contains allergy-causing substances such as formaldehyde which can damage the skin of the wearer.

The invention is therefore based on the object of developing a method and a device for carrying out the method of the type mentioned in such a way that, with substantially improved wearing comfort of textile fabrics, less expensive production is ensured.

To achieve the object, the invention is characterized by the technical teaching of claim 1, in which a novel method is claimed.

A device necessary to carry out the method is also claimed to be essential to the invention.

The invention accordingly relates to all textile fabrics, namely woven, knitted and nonwoven fabrics.

The essential difference between the present invention and the prior art mentioned at the outset is that the treatment with an alkali takes place without tension and takes place before the shaping process.

Another essential difference is that the textile treated with sodium hydroxide solution is deformed and remains fixed in the mold, even if the textile undergoes a subsequent neutralization process.

This is the main difference from the prior art mentioned at the outset, because in the prior art the neutralization and washing take place outside the mold, as a result of which the high, impermissible degrees of shrinkage mentioned at the outset had to be accepted.

According to the invention, several different possibilities are provided for the final treatment of the product, all of which should be encompassed by the inventive concept.

In a first process it is proposed that the final treatment of the product also takes place in the form ie the product is washed in the mold and dried after neutralization.

In a second, modified process feature, after neutralization in the mold, the product is removed from the mold, washed and then dried.

Tests by the applicant have shown that the steps of the alkali treatment according to the invention and the subsequent reshaping of the textile fabric in the mold, with all treatment steps being carried out with the mold closed, lead to a reorientation of the cellulose molecules, which leads to the required dimensional stability . There is therefore no need for crosslinking, as is done with synthetic resin impregnations, because a similar dimensionally stable structure is generated by the reorientation of the cellulose molecules according to the invention. On the contrary, the tear resistance is greatly reduced by the synthetic resin impregnation of the fabric, which is to be regarded as disadvantageous. This affects the subsequent sewing of the article and also affects the wearing properties of this article.

In the method according to the invention, the reorientation of the cellulose molecules improves the tensile strength, something which has not yet been recognized and which therefore gives the article produced in this way optimum properties in processing and wearing.

In addition, the leaching according to the invention has the advantage that a in the goods treated in this way A glossy effect is achieved, which is particularly desirable for corsetry, and which can otherwise only be achieved through a complex finish.

An additional advantage of the proposed method is that, due to the increased tear strength achieved, it is now possible for the first time that the goods can also be embroidered, which was not previously possible. Because of the reduced tensile strength of corsetry impregnated with plastic, embroidery was not sensible, because the embroidery holes tore out when worn and damage to the stitches occurred.

Linen fibers, jute, hemp, kapok and sisal are particularly suitable as further natural fibers which can be shaped as textile fabrics according to the present invention, and all fiber mixtures can also be shaped as textile fabrics according to the teaching of the technical invention. In addition, synthetic fibers and mixtures of synthetic and natural fibers.

It is important with the invention that the end product of the present method is without chemical residues and therefore makes it particularly comfortable to wear, so that allergenization of the user is definitely excluded.

The previously mentioned term "fiber mixture" includes all synthetic fibers that can be processed with the natural fiber mentioned, so that textile fabrics are made therefrom that offer the highest wearing comfort.

To simplify the description below, in the following always assumed a knitted cotton fabric, which is formed according to the technical teaching of the invention. However, this does not limit the scope of the invention, because the invention relates to all textile fabrics mentioned above.

An important feature of the specified method is that the mechanical deformation of the textile fabric takes place when the textile fabric is under the action of the alkali mentioned. Tests by the applicant have shown that the action of sodium hydroxide on natural fibers leads to a shrinking process which leads to a shrinkage of the entire textile fabric. This shrunk product is then subjected to mechanical reshaping, whereby this reshaping partially eliminates the shrinkage previously caused in the caustic bath, which causes the fibers in the reshaping area to stretch due to the action of the mechanical reshaping tools and the shrinkage in this area accordingly is partially canceled.

After the forming process, this textile fabric is then treated in such a way that the lye is completely removed from the fabric, as a result of which this textile fabric is practically returned to its original state. This means that a reshaped, residue-free textile fabric according to the invention is produced, which makes it extremely comfortable to wear.

Of course, the present invention includes a certain pretreatment of the cotton knitwear at the entrance of the processing, which z. B. can be bleached, prewashed or dyed.

It is also possible according to the invention to process the obtained starting product (end product) of the method according to the invention as intended, such as. B. coloring, applying plasticizers, using optical brighteners, adding finishing agents, attaching handle variators and the like. More.

It was mentioned above that the shrinkage of a natural fiber is used in an alkali bath in order to subsequently achieve mechanical deformation of the alkali-treated textile fabrics.

In another embodiment of the present invention, in an analogous application of the method, it is provided that the dry goods are first formed and subjected to the leaching process when the forming is fixed (i.e. remaining in the forming tool).

It is important in both methods that the formed goods in the forming tool are subjected to the subsequent neutralization in order to remove the sodium hydroxide solution.

It is not absolutely necessary for the solution to remain if the textile fabric remains in the mold, if after the removal of the sodium hydroxide solution further treatment steps are mentioned, which were mentioned above.

In a preferred embodiment of the present invention, it is preferred to use sodium hydroxide solution which has a concentration of 30 ° Be.

It is preferably carried out in a temperature range of about 60 °.

After the cotton knitwear has lingered in the lye bath, the lye is then removed as far as possible from the textile ware and then squeezed out, in order to subsequently subject it to mechanical shaping.

In another embodiment of the present invention, an application of the alkali via a foulard is proposed instead of the alkali bath.

Such a foulard consists of two counter-rotating rollers which define between them a nip through which the goods to be treated pass, the liquor solution being arranged above the nip.

Likewise, the liquor liquor can also be arranged below the nip, after which the goods then run through a liquor bath arranged under the padder.

All mechanical forming processes are preferred as the forming of this lye-treated goods, namely die forming, free forming, roll forming, blow molding, vacuum deep drawing and shrinking.

All of the above-mentioned forming processes require a tool shape with which the desired final shape of the knitted fabric is to be achieved.

In the case of die forming, a die, ie So worked with male and female, while in free forming only one female is molded into the flat fabric. In the case of roll forming, forming is carried out in a roll gap, the shaping forming being achieved by corresponding recesses in one roll, into which corresponding projections on the opposite roll engage.

During blow molding, this flat structure is drawn over a mandrel with possibly high temperatures, while in vacuum deep drawing the flat structure is also drawn over a tool mold under vacuum.

When shrinking on, it is provided that an upward convex tool shape is covered with the textile fabric, which is then subsequently soaked by appropriate lye treatment (e.g. via spray nozzles) and is thus subjected to a shrinking process. It is usually provided here that this textile fabric is clamped at the edge regions in order to take advantage of the shrinkage of the goods and thus to adapt to the shape of the tool.

• 1. Einbringen der trockenen, gegebenenfalls vorbehandelten Maschenware in ein Laugenbad
• 2. Verweilenlassen des Textils im Laugenbad für eine bestimmte Zeit, bis der gewünschte Schrumpfungsgrad erreicht ist
• 3. Entfernen der behandelten Ware aus dem Laugenbad mit teilweise mechanischer Entfernung der Lauge aus dem Textil
• 4. Unterwerfen einer mechanischen Umformung
• 5. Entfernen der Natronlauge aus dem Textil bei beibehaltener Umformung
• 6. Endbehandlung des umgeformten Textilgebildes.

The method according to the invention is therefore claimed in the context of two main claims (main claim and secondary claim), the first solution scheme having the following sequence:

• 1. Introduce the dry, optionally pretreated knitted fabric into a soapy bath
• 2. Letting the textile linger in the lye bath for one certain time until the desired degree of shrinkage is reached
• 3. Removal of the treated goods from the lye bath with partial mechanical removal of the lye from the textile
• 4. Subject to mechanical deformation
• 5. Remove the sodium hydroxide solution from the textile while maintaining the deformation
• 6. Final treatment of the formed textile structure.

• 1. Einbringen des gegebenefalls vorbehandelten Textils in eine mechanische Umformung,
• 2. Einbringen des umgeformten Textils zusammen mit dem Umformwerkzeug in ein Laugenbad,
• 3. Entfernung der Lauge durch Spülen und/oder Säurebehandlung, während die Maschenware auf dem Umformwerkzeug verbleibt,
• 4. Endbehandeln des umgeformten Textilgebildes.

According to the second solution scheme, for which separate protection is claimed, the following procedure applies:

• 1. introducing the optionally pretreated textile into a mechanical forming,
• 2. introducing the formed textile together with the forming tool into an alkali bath,
• 3. removal of the alkali by rinsing and / or acid treatment while the knitted fabric remains on the forming tool,
• 4. Final treatment of the formed textile structure.

The process steps to be applied after the shaping can, for. B. rinsing the fabric at 80 ° C z. B. under pressure with spray nozzles and in combination with a dipping process. Several rinsing processes can be switched in series. After rinsing, neutralize with a organic or inorganic acid by spraying and / or immersion, preferably formic or acetic acid.

Then it is rinsed cold, the goods are dried or the excess liquid is sucked off the goods.

Plasticizers can then be sprayed on or optical brighteners applied. The goods are then finally dried.

The product manufactured in this way is characterized in that it contains no synthetic resins or other foreign polymers for fixing the deformation. The chemicals necessary for fixing the shape are completely washed out, which means that a physiologically high-quality article, e.g. B. Bra is created.

• es werden keine formaldehydhaltigen Produkte eingesetzt, d.h. es entsteht bei der Verarbeitung (Abwasser/Abluft) kein Formaldehyd
• es wird zur Fixierung der Verformung nur Lauge, bevorzugt Natronlauge eingesetzt, welche mehrfach aufkonzentriert und wiederverwendet werden kann. Zur Entsorgung kann die Lauge mit Säure neutralisiert werden.

This type of deformation not only leads to a formaldehyde-free, skin-compatible brassiere (e.g. advantageous for allergy sufferers), but also offers advantages during manufacture.
For example:

• no formaldehyde-containing products are used, ie no formaldehyde is produced during processing (waste water / exhaust air)
• it is used only to fix the deformation, preferably caustic soda, which can be concentrated and reused several times. The alkali can be neutralized with acid for disposal.

The advantages of the process according to the invention are that the tensile strength of the goods is significantly improved by the alkali treatment which takes place. as well as the feel and gloss of the treated fiber. With conventional deformation, which takes place at relatively high temperatures, there is a risk of yellowing of the natural fiber, while this is definitely excluded in the method according to the invention. In addition, the advantage is that the fabric produced with the method according to the invention has an improved absorbency compared to a fabric thermally treated according to the prior art. In addition, the extensibility is significantly improved. It is now possible for the first time to produce items of laundry with the highest wearing comfort that have a permanent three-dimensional deformation, which is retained even after multiple washing.

This also results in a more cost-effective production of, in particular, brassiere cups and cups, because there is no need for complex assembly.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another. All information and features disclosed in the documents, including the summary, in particular the spatial design shown in the drawings are claimed as essential to the invention, insofar as they are new to the prior art, individually or in combination.

In the following, the invention is explained in more detail with reference to drawings showing several embodiments. Here, from the drawings and their description, further features and advantages of the invention that are essential to the invention emerge.

Figur 1:

schematisiert der Verfahrensablauf nach der Erfindung in einer ersten Ausführungsform;

Figur 2:

schematisiert der Verfahrensablauf in einer zweiten Ausführungsform;

Figur 3:

Seitenansicht einer Gesenk-Umformmaschine;

Figur 4:

schematisiert in Seitenansicht die Umformung durch Schrumpfen;

Figur 5:

ein abgewandeltes Verfahrensschema gegenüber Figur 1;

Figur 6:

eine weitere Abwandlung eines Verfahrensschemas.

Show it:

Figure 1:

schematically the process flow according to the invention in a first embodiment;

Figure 2:

schematically the process flow in a second embodiment;

Figure 3:

Side view of a die-forming machine;

Figure 4:

schematized in side view the deformation by shrinking;

Figure 5:

a modified process diagram compared to Figure 1;

Figure 6:

another modification of a process scheme.

According to FIGS. 1 and 2, a fabric roll 2 is unwound from a fabric roll 1, which may consist of a treated or untreated cotton knitwear, and introduced into a lye bath 3 via deflection rollers 4.

There, the fabric web 2 stays for a certain time in the lye bath 3 of z. B. in the range between 10 and 40 seconds.

The fabric web 2 is then passed through squeeze rollers 5, where a large part of the alkali is removed from the goods. Subsequently, the fabric is divided by one or more knives 6 into textile structures 7 which are still saturated with sodium hydroxide solution. These textile structures 7 undergo mechanical shaping 8, a die being described in more detail in FIGS. 1 to 3. The die 9 essentially consists of one or more forming dies which are guided against the stretched textile structure 7 so as to cause the previously shrunk textile fabric to stretch in the region of the forming zones.

Following the mechanical shaping, a drying unit 10 can be connected in order to dry and further process the goods treated with the alkali.

On the other hand, it is preferred if, instead of drying, the goods still in the die 9, which is now formed as a textile structure 7 ', are transferred to one or more baths.

In a first embodiment, it is possible that a rinsing bath 11 is used as the first bath, into which the textile structure 7 'resting in the die 9 is inserted, in order to remove part of the sodium hydroxide solution from the structure 7'.

It is also possible in another embodiment of the invention to provide a neutralization bath 12 as the first bath, where the lye is neutralized.

One or more rinsing baths 11 can be connected in series, different rinsing processes being carried out at different temperatures.

After passing through the neutralization bath 12, the goods are fed to a suction station 13, where the remaining liquid for the most part Will get removed. A final treatment 14 can then be connected.

It is added to the above-mentioned drying 10 that lye bath 3 can also be used with lyes of relatively low concentration, the drying concentration 10 achieving the effective concentration of the lye.

In the exemplary embodiment according to FIG. 2, it is provided that the dry fabric web 2 is immediately subjected to mechanical shaping 8 and the shaping tool is lowered into the suds bath 3 together with the deformed textile structure 7.

Thereafter - after the mechanical shaping 8 - the deformed textile structure 7 'remaining in the die 9 is again fed to a number of rinsing and neutralizing baths 11, 12, 13, after which a finishing treatment 14 can also take place.

It is also provided that the die 9 remains in the lye bath 3 for a certain time in order to allow the shrinking process to develop to the desired degree of shrinkage. After the shrinking process, a dwell stage can be inserted before the rinsing and post-treatment processes. The dwell is preferably at room temperature with the exclusion of air.

Such a mechanical deformation is shown as an exemplary embodiment in FIG. 3, a lifting drive 18 which drives a die 9 in the vertical direction being arranged in a column frame 17. One or more tool shapes 23 are on the die 9 arranged, under which a clamping frame 19 can be raised and lowered.

First, the clamping frame 19 moves onto the support frame 21 on which the textile structure 7 lies flat. The clamping frame 19 then clamps this textile structure 7 at least in the edge regions, so that the tool molds 23 push down the textile structures 23 Tool molds press the textile structure down and carry out the reshaping in the desired regions.

The support frame 20 is in this case mounted in the area of a support frame 21, in which a trough 22 is also arranged for collecting flowing liquid. In addition to the lifting drive shown, which can be moved in the arrow directions 15 and in the opposite direction, it is of course also possible to carry out horizontal displacement movements.

Instead of the linear actuator shown here, endless deformation processes can also be carried out, i.e. Deformations in the area of a nip, which is formed by two opposing, opposing deformation rollers.

Instead of the discontinuous deformation process described here, continuous deformation processes can also be used and are claimed accordingly.

A free forming is shown in FIG. 4, wherein the textile structure 7 to be formed is clamped over a tool form 23. It is then treated with the alkali via spray nozzles 24, which leads to a Shrinkage occurs and the textile fabric in the form of the deformed structures 7 ', 7''fits positively on the mold 23.

The other liquids, namely the neutralization solution and the rinsing solutions, can also be introduced to the textile structure via the spray nozzles 24.

FIG. 5 shows a modified exemplary embodiment of a method in comparison to the method according to FIG. 1.

The same parts have been provided with the same reference numerals and only the differences from the method according to FIG. 1 are explained below.

The goods are namely removed from the mold (die 9) after the neutralization bath 12 and thus form the textile structure 7 ″.

It is then washed in a washing machine with water in the temperature range between 30 ° and 90 ° and then spun. Surfactants can be added during the washing process.

After being spun off in the washing machine, the textile fabric is put into a dryer, where it is dried in the range from dry to iron-damp.

The textile structure 7 * removed from the dryer is then stretched onto a heated mold 28, in which case the shape in the heated mold should be the same as that described above in the same way Die 9 was manufactured.

With the clamping on the heated mold 28, the deformations that occurred during the washing process and the subsequent drying process are to be reversed, and any possible creasing should also be removed.

The mold is heated in the range of approximately 60 ° to 200 °, which depends on the length of time the textile structure remains in the mold and the sensitivity of the textile.

In Figure 6 the same processes as in Figure 5 are described, i.e. the textile structure 7 ″ is first washed in a washing machine 26.

After washing and spinning the textile, it leaves the washing machine 26 as a textile structure 7x and is immediately clamped onto the heated mold 28 and dried there.

With regard to the drying temperatures and the residence time of the textile structure 7 '' 'in the form 28, reference is made to the preceding description.

FIGS. 5 and 6 also have in common that drying 10 can take place as an intermediate stage after the shaping in the mechanical shaping 8 and before the neutralization in the neutralizing bath 12.

The intermediate drying process (drying 10) enables an increased alkali concentration in the textile structure 7 'to be achieved.

Instead of the previously mentioned caustic concentration of the sodium hydroxide solution of 30 ° Bé, other concentrations can also be used. The lye temperature can also be varied.

Instead of the sodium hydroxide solution described, other alkalis can also be used, such as. B. Potash, triethanolamine, lithium hydroxide and mixtures of the above chemicals.

Likewise, the process parameters mentioned can be changed within wide limits, it being only essential that the goods must be shrunk accordingly and the mechanical shaping described causes the fiber to stretch in the shaping area. DRAWING LEGEND 1 Roll of fabric 26 Washing machine 2nd Fabric panel 27 dryer 3rd Lye bath 28 heated mold 4th Pulley 5 Squeeze roller 6 knife 7.7 ', 7'',7''', 7 *, 7 **, 7x Textile structures 8th mechanical forming 9 Die 10th Drying 11 Rinsing bath 12th Neutralizing bath 13 Suction station 14 Final treatment 15 Arrow direction 17th Pillar frame 18th Linear actuator 19th Clamp frame 20th Support frame 21 Support frame 22 Tub 23 Tool shape 24th Spray nozzles 25th Dwell level / dwell

Claims (12)

Process for forming textile fabrics (7 ', 7'') from pure natural fibers or mixed fibers, the textile fabric (7', 7 '') being exposed to lye, characterized in that
that a) the textile fabric (7 ', 7'') is treated for a certain time until a desired shrinking process has occurred, b) the alkali is then removed mechanically, in particular by squeezing, c) the textile fabric (7 ', 7'') is then mechanically deformed, d) the remaining lye is completely removed by washing out, adding neutralizing agents or a combination thereof, while the textile fabric is fixed in shape and e) the textile fabric (7 ', 7'') is finished according to the subsequent use. Method for reshaping textile fabrics according to claim 1, characterized in that the textile fabric (7 ', 7'') runs through an alkali bath (3) in the first process step. Method for forming textile fabrics according to one of claims 1 to 2, characterized in that the forming process (8) is carried out by die forming (9), roller forming, blow molding, vacuum forming or shrinking. Process for forming textile fabrics from pure natural fibers or mixed fibers preferably according to claim 1, characterized in that a) the dry, textile fabric (7 ', 7'') is molded into the forming device, b) is exposed to the action of an alkali, c) the textile fabric (7 ', 7'') is treated for a certain time until the desired shrinking process has occurred, d) the lye is completely removed by washing, adding neutralizing agents or a combination thereof and e) the textile fabric (7 ', 7'') is finished according to the subsequent use. Process for forming textile fabrics according to one of claims 1 to 4, characterized in that another inorganic lye or an organic lye is used for the shrinking step. Process for forming textile fabrics according to one of Claims 1 to 5, characterized in that the textile fabric (7 ', 7'') is subjected to a neutralization process with water and / or acid in the final treatment. Method according to one of claims 1 to 6, characterized in that the sodium hydroxide solution has a concentration of about 30 Bè. Method according to one of claims 1 to 7, characterized in that the sodium hydroxide solution has a temperature of about 60 ° C. Method according to one of claims 1 to 8, characterized in that according to method step e) the textile fabric is not on the mold during the final treatment. Method according to one of claims 1 to 8, characterized in that according to method step e) the textile fabric is on the mold during the final treatment. Textile fabric which is formed, characterized in that it is free of formaldehyde. Textile, reshaped fabric, characterized in that it is free of chemicals.

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